qemu/disas/libvixl/a64/decoder-a64.h

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// Copyright 2013, ARM Limited
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of ARM Limited nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#ifndef VIXL_A64_DECODER_A64_H_
#define VIXL_A64_DECODER_A64_H_
#include <list>
#include "globals.h"
#include "a64/instructions-a64.h"
// List macro containing all visitors needed by the decoder class.
#define VISITOR_LIST(V) \
V(PCRelAddressing) \
V(AddSubImmediate) \
V(LogicalImmediate) \
V(MoveWideImmediate) \
V(Bitfield) \
V(Extract) \
V(UnconditionalBranch) \
V(UnconditionalBranchToRegister) \
V(CompareBranch) \
V(TestBranch) \
V(ConditionalBranch) \
V(System) \
V(Exception) \
V(LoadStorePairPostIndex) \
V(LoadStorePairOffset) \
V(LoadStorePairPreIndex) \
V(LoadStorePairNonTemporal) \
V(LoadLiteral) \
V(LoadStoreUnscaledOffset) \
V(LoadStorePostIndex) \
V(LoadStorePreIndex) \
V(LoadStoreRegisterOffset) \
V(LoadStoreUnsignedOffset) \
V(LoadStoreExclusive) \
V(LogicalShifted) \
V(AddSubShifted) \
V(AddSubExtended) \
V(AddSubWithCarry) \
V(ConditionalCompareRegister) \
V(ConditionalCompareImmediate) \
V(ConditionalSelect) \
V(DataProcessing1Source) \
V(DataProcessing2Source) \
V(DataProcessing3Source) \
V(FPCompare) \
V(FPConditionalCompare) \
V(FPConditionalSelect) \
V(FPImmediate) \
V(FPDataProcessing1Source) \
V(FPDataProcessing2Source) \
V(FPDataProcessing3Source) \
V(FPIntegerConvert) \
V(FPFixedPointConvert) \
V(Unallocated) \
V(Unimplemented)
namespace vixl {
// The Visitor interface. Disassembler and simulator (and other tools)
// must provide implementations for all of these functions.
class DecoderVisitor {
public:
enum VisitorConstness {
kConstVisitor,
kNonConstVisitor
};
explicit DecoderVisitor(VisitorConstness constness = kConstVisitor)
: constness_(constness) {}
virtual ~DecoderVisitor() {}
#define DECLARE(A) virtual void Visit##A(const Instruction* instr) = 0;
VISITOR_LIST(DECLARE)
#undef DECLARE
bool IsConstVisitor() const { return constness_ == kConstVisitor; }
Instruction* MutableInstruction(const Instruction* instr) {
VIXL_ASSERT(!IsConstVisitor());
return const_cast<Instruction*>(instr);
}
private:
VisitorConstness constness_;
};
class Decoder {
public:
Decoder() {}
// Top-level wrappers around the actual decoding function.
void Decode(const Instruction* instr) {
std::list<DecoderVisitor*>::iterator it;
for (it = visitors_.begin(); it != visitors_.end(); it++) {
VIXL_ASSERT((*it)->IsConstVisitor());
}
DecodeInstruction(instr);
}
void Decode(Instruction* instr) {
DecodeInstruction(const_cast<const Instruction*>(instr));
}
// Register a new visitor class with the decoder.
// Decode() will call the corresponding visitor method from all registered
// visitor classes when decoding reaches the leaf node of the instruction
// decode tree.
// Visitors are called in order.
// A visitor can be registered multiple times.
//
// d.AppendVisitor(V1);
// d.AppendVisitor(V2);
// d.PrependVisitor(V2);
// d.AppendVisitor(V3);
//
// d.Decode(i);
//
// will call in order visitor methods in V2, V1, V2, V3.
void AppendVisitor(DecoderVisitor* visitor);
void PrependVisitor(DecoderVisitor* visitor);
// These helpers register `new_visitor` before or after the first instance of
// `registered_visiter` in the list.
// So if
// V1, V2, V1, V2
// are registered in this order in the decoder, calls to
// d.InsertVisitorAfter(V3, V1);
// d.InsertVisitorBefore(V4, V2);
// will yield the order
// V1, V3, V4, V2, V1, V2
//
// For more complex modifications of the order of registered visitors, one can
// directly access and modify the list of visitors via the `visitors()'
// accessor.
void InsertVisitorBefore(DecoderVisitor* new_visitor,
DecoderVisitor* registered_visitor);
void InsertVisitorAfter(DecoderVisitor* new_visitor,
DecoderVisitor* registered_visitor);
// Remove all instances of a previously registered visitor class from the list
// of visitors stored by the decoder.
void RemoveVisitor(DecoderVisitor* visitor);
#define DECLARE(A) void Visit##A(const Instruction* instr);
VISITOR_LIST(DECLARE)
#undef DECLARE
std::list<DecoderVisitor*>* visitors() { return &visitors_; }
private:
// Decodes an instruction and calls the visitor functions registered with the
// Decoder class.
void DecodeInstruction(const Instruction* instr);
// Decode the PC relative addressing instruction, and call the corresponding
// visitors.
// On entry, instruction bits 27:24 = 0x0.
void DecodePCRelAddressing(const Instruction* instr);
// Decode the add/subtract immediate instruction, and call the correspoding
// visitors.
// On entry, instruction bits 27:24 = 0x1.
void DecodeAddSubImmediate(const Instruction* instr);
// Decode the branch, system command, and exception generation parts of
// the instruction tree, and call the corresponding visitors.
// On entry, instruction bits 27:24 = {0x4, 0x5, 0x6, 0x7}.
void DecodeBranchSystemException(const Instruction* instr);
// Decode the load and store parts of the instruction tree, and call
// the corresponding visitors.
// On entry, instruction bits 27:24 = {0x8, 0x9, 0xC, 0xD}.
void DecodeLoadStore(const Instruction* instr);
// Decode the logical immediate and move wide immediate parts of the
// instruction tree, and call the corresponding visitors.
// On entry, instruction bits 27:24 = 0x2.
void DecodeLogical(const Instruction* instr);
// Decode the bitfield and extraction parts of the instruction tree,
// and call the corresponding visitors.
// On entry, instruction bits 27:24 = 0x3.
void DecodeBitfieldExtract(const Instruction* instr);
// Decode the data processing parts of the instruction tree, and call the
// corresponding visitors.
// On entry, instruction bits 27:24 = {0x1, 0xA, 0xB}.
void DecodeDataProcessing(const Instruction* instr);
// Decode the floating point parts of the instruction tree, and call the
// corresponding visitors.
// On entry, instruction bits 27:24 = {0xE, 0xF}.
void DecodeFP(const Instruction* instr);
// Decode the Advanced SIMD (NEON) load/store part of the instruction tree,
// and call the corresponding visitors.
// On entry, instruction bits 29:25 = 0x6.
void DecodeAdvSIMDLoadStore(const Instruction* instr);
// Decode the Advanced SIMD (NEON) data processing part of the instruction
// tree, and call the corresponding visitors.
// On entry, instruction bits 27:25 = 0x7.
void DecodeAdvSIMDDataProcessing(const Instruction* instr);
private:
// Visitors are registered in a list.
std::list<DecoderVisitor*> visitors_;
};
} // namespace vixl
#endif // VIXL_A64_DECODER_A64_H_